RGB to CMYK Color Converter

Color Picker

rgb(255, 0, 0)

Color Shades

Color Combinations

About RGB and CMYK Colors

RGB (Red, Green, Blue) and CMYK (Cyan, Magenta, Yellow, Key/Black) are two fundamental color models used in digital and print design respectively.

RGB (Red, Green, Blue)

RGB is an additive color model used for digital displays where colors are created by combining red, green, and blue light. Each component ranges from 0 to 255. For example, pure red is (255, 0, 0) in RGB. This model is used for all digital displays including computer monitors, TVs, and mobile devices. RGB colors tend to be more vibrant than CMYK colors because they use light to create colors rather than pigments.

CMYK (Cyan, Magenta, Yellow, Key)

CMYK is a subtractive color model used in color printing. Colors are created by subtracting varying percentages of cyan, magenta, yellow, and black ink. Each component ranges from 0% to 100%. Pure red in CMYK is approximately (0%, 100%, 100%, 0%). The "K" in CMYK stands for "key" (black) which is used for depth and detail. CMYK has a smaller color gamut than RGB, meaning some RGB colors cannot be perfectly reproduced in CMYK.

RGB to CMYK Conversion Process

  1. Convert RGB values to the range 0-1 by dividing by 255
  2. Calculate the Key (black) component: K = 1 - max(R, G, B)
  3. If K = 1 (black), set CMYK to (0, 0, 0, 100)
  4. Otherwise, calculate the other components:
    • Cyan: C = (1 - R - K) / (1 - K)
    • Magenta: M = (1 - G - K) / (1 - K)
    • Yellow: Y = (1 - B - K) / (1 - K)
  5. Convert all components to percentages (multiply by 100 and round)

Example #1

Convert pure red RGB (255, 0, 0) to CMYK:

RGB = (255, 0, 0)

Normalized RGB = (1, 0, 0)

K = 1 - max(1, 0, 0) = 0

C = (1 - 1 - 0) / (1 - 0) = 0

M = (1 - 0 - 0) / (1 - 0) = 1 (100%)

Y = (1 - 0 - 0) / (1 - 0) = 1 (100%)

CMYK = (0%, 100%, 100%, 0%)

Example #2

Convert dark blue RGB (0, 0, 128) to CMYK:

RGB = (0, 0, 128)

Normalized RGB ≈ (0, 0, 0.5)

K = 1 - max(0, 0, 0.5) = 0.5

C = (1 - 0 - 0.5) / (1 - 0.5) = 1 (100%)

M = (1 - 0 - 0.5) / (1 - 0.5) = 1 (100%)

Y = (1 - 0.5 - 0.5) / (1 - 0.5) = 0

CMYK ≈ (100%, 100%, 0%, 50%)

Common RGB to CMYK Examples

  • rgb(255, 255, 255) → (0%, 0%, 0%, 0%) (white)
  • rgb(0, 0, 0) → (0%, 0%, 0%, 100%) (black)
  • rgb(255, 0, 0) → (0%, 100%, 100%, 0%) (red)
  • rgb(0, 255, 0) → (100%, 0%, 100%, 0%) (green)
  • rgb(0, 0, 255) → (100%, 100%, 0%, 0%) (blue)
  • rgb(255, 255, 0) → (0%, 0%, 100%, 0%) (yellow)
  • rgb(0, 255, 255) → (100%, 0%, 0%, 0%) (cyan)
  • rgb(255, 0, 255) → (0%, 100%, 0%, 0%) (magenta)
  • rgb(128, 128, 128) → (0%, 0%, 0%, 50%) (gray)

When converting from RGB to CMYK, some color shift may occur because CMYK cannot reproduce all RGB colors. This is especially noticeable with very bright, saturated colors. For print design, it's important to work in CMYK color space to ensure your colors print as expected.

RGB to CMYK FAQ

What's the difference between RGB and CMYK?

RGB is an additive color model used for digital displays (light-based), while CMYK is a subtractive color model used for printing (ink-based). RGB has a wider color gamut than CMYK, meaning some RGB colors cannot be perfectly reproduced in CMYK.

When should I use CMYK instead of RGB?

Use CMYK when designing for print (business cards, brochures, magazines, etc.). Use RGB when designing for digital displays (websites, apps, digital ads). Always convert to CMYK before sending files to print to ensure color accuracy.

Are all RGB colors perfectly convertible to CMYK?

No, CMYK has a smaller color gamut than RGB. Very bright, saturated RGB colors often cannot be perfectly reproduced in CMYK and will appear slightly duller when printed. This is why professional designers often work in CMYK when creating print materials.

Why does my printed color look different than on screen?

This is due to the difference between RGB (screen) and CMYK (print) color spaces, and also because screens emit light while printed materials reflect light. For best results, use CMYK color values when designing for print and request a physical proof before large print runs.